Opiate addiction is a major public health problem with an early age of onset and high comorbidity with other psychiatric disorders, including depression, anxiety disorders, other drug abuse, alcoholism, and anti-social personality. Despite this, there are virtually no data on the clinical, psychiatric, and neurologic status of children of opiate addicts in their school- age years (6 to 17 years). This is a 5-year study of 600 children of opiate addicts, 6 to 17 years of age, stratified by race, which will compare these children with already collected samples of children of normals (never psychiatrically ill) and children of parents with major depression. These children will undergo intensive clinical study with psychiatric diagnostic and neurological assessment to determine their risk for childhood psychiatric disorders (including conduct disorder, substance abuse, and affective and anxiety disorders) and neurocognitive deficits (including attention deficit disorder, development disorders, learning disabilities, I.Q., neurological soft signs, and poor motor proficiency), and impairment in school and social functioning. This design will determine whether the excess risk for childhood disorders and impairments is specific to children of opiate addicts or non-specific resembling the risk conveyed to offspring of parents with another psychiatric disorder, major depression. Risk factors predictive of specific childhood disorders and impairments will be determined by comparing affected and non-affected children within the opiate sample. This will explore, among other hypotheses, whether childhood psychopathology breeds true: that is, whether childhood depression will be predicted by parental major depression, whether conduct disorder will be predicted by parental sociopathy, and whether neurological and neurocognitive impairment will be predicted by intra-uterine drug exposure or perinatal complications. The effects of mediating and moderating factors, such as family discord or intrauterine drug exposure on risk, will be assessed. Information on the children will be collected from multiple informants, including direct interview with the child, the mother, and, if possible, the father, and/or other key informants, as necessary. In addition, there will be direct diagnostic assessment of the parents and family history data about other first-degree relatives, including the parents' siblings and own parents. Findings of this study should help in planning future preventive interventions for children of opiate addicts.